MANILA, Dec. 24 -- Police suspect murder to be the primary motive behind the Dec. 11 mid-air explosion aboard a Philippine Airlines plane bound for Japan that killed a single passenger, investigators said Saturday. A top Philippine National Police official who requested anonymity said the blast was confined to a limited area and probably was meant for only Japanese national Haruki Ikegami, the lone fatality. He said investigators were looking into Ikegami's background as they suspect he may have been involved in a 'murder-for-insurance' conspiracy or was the victim of a business rivalry. Reports said fragments of what could have been a bomb, including shards of black plastic, adhesive tape and piece of an alarm clock, were recovered around the blast area and from Ikegami's body. Experts say the bomb may have been planted in the life jacket underneath Ikegami's seat. Seven other passengers were wounded in the explosion that forced the pilot of PAL flight PR-434 to make an emergency landing at Japan's Naha airport. The latest findings, police said, should discount the claim of responsibility by Abu Sayyaf, a shadowy Muslim militant group from the southern Philippines. A few hours after the explosion a caller identifying himself as a member of the Abu Sayyaf claimed responsibility for the explosion. But authorities expressed doubts, saying the 'rag-tag' group did not have the expertise to plant a bomb on an international flight. Criminal Investigation chief Romeo Acop said investigators were checking the background of all passengers on the flight for possible clues.
Acop said they had already started investigating two batches of passengers and the PAL service crew. Police are also looking into the possible involvement of Yakuza gangsters or of the radical Japanese Red Army. PAL flight 434, carrying 293 passengers and crew, was headed for Tokyo from Cebu in the central Philippines when the explosion occurred.